Signal converter noise shaper ad converter and da converter

ABSTRACT

The present invention provides a first-order delta-sigma AD converter adapted to conduct noise shaping and having a quantizer arranged such that, when the amplitude of an input signal entered into the quantizer is small, the amplitude of a difference signal between the input signal entered into the quantizer and an output signal therefrom, is small. It is therefore possible to achieve an efficient AD- or DA-converter reduced in power consumption, which satisfies the transmission characteristics of the specifications of CCITT G.714 based on a method of PCM-encoding an audio frequency band signal stipulated in the specifications of CCITT G.711.



